In cloud computing, a cloud server is typically responsible for providing and managing applications running at the cloud server. The data of the applications can be stored remotely in a cloud database. These applications are designed only for running on top of the special operating system of the cloud server. The cloud server and the computing devices have different operating systems and running environments. Typically applications designed for the cloud may not be downloaded and installed by the users on their own computing devices, because processing and storage for the applications are maintained by the cloud server and cloud database.